Same sex marriage is not an issue of equality nor the success of any couple’s marriage. It is not about the value or validity of homosexuality. The issue is about the link between the state and marriage in civil society. Who decides what marriage is and what it’s for?

Marriage is neither essentially religious nor a product of tradition. It is not the child of the state.

Neither is marriage what Lynne Featherstone the British Equalities Minister claims. “Marriage is a right of passage for couples who want to show they are in a committed relationship, for people who want to show they have found love and wish to remain together until death do them part.” Her historical vision is limited; her logic is deficient and her fusion of the Anglican Prayer Book with modern idiom disingenuous.

Marriage is the consequence of who we are. We do not make it; it makes us. Marriage would not exist if there were not two complementary sexes. And that’s why it does exist.

We are male and female. In the simple and hopeful business of being alive we have children in a union of consenting responsibility, love and thankfulness.

It is the fusing of two opposite halves of the human being through which new life may be created.

That some couples decide not to get married does not change the biology. That some cannot have children or decide not to is beside the point.

The so-called conservative case for same-sex marriage favoured by the British Prime Minister (and apparently by our own Prime Minister) tumbles out of a category error. “Marriage is a good thing. It stabilises the lives of those who participate; especially men. Therefore they should be able to marry each other if they are committed.”

But as soon as same-sex marriage is granted, marriage has been changed to something profoundly different; from an institution prior to the state to one determined by the state.

Of course the state has had regulations around marriage for a very long time. But with the advent of same-sex marriage we have given the state a role it never had.

If the state defines marriage the family is no longer an independent institution of civil society declaring daily to the state its limitations. While we are a long way from Stalinism in New Zealand this was the kind of power Stalin wanted.

If the state passes a law that changes the nature of marriage, and consequently family, then every citizen’s liberty is endangered. Why? That area of most intimate human life that was once outside the power of the state to control will be watered down. In becoming the author of marriage the state must eventually erode religious freedom and then freedom of speech.

The ‘new marriage’ will become an institution that the state must enforce. Any exemption given initially to the church will be temporary and dependent only on threatened moral sensitivities. It will not be enough for the church to be good or even right when all the social forces are moving against it.

Human rights were once seen as a cornerstone of liberty because they were the consequence of a free society aware of state limits. They protected the independent spheres of authority in civil society (marriage, family and religion and others).

If marriage becomes what the state determines citizens will no longer have any legal, or ultimately moral framework independent of the state to argue their case about family form. Families will become what the state decides. In France this is probably the pivotal constitutional issue around which the same sex marriage debate spins.

It is doubtful there is any society known to history or anthropology where social order has not been based on marriage between a man and a woman.

It has always been an historical and universal understanding of a binding contract to enhance social order and encourage responsible child care. Societies that fail to understand this devalue their children. We should know that. We have plenty of evidence.

We have never had such a plethora of data pointing out the fundamental economic, social and psychological benefits of vigorous and enduring married families. Marriage is pivotal to intergenerational order. Without it we have a shambles and increasing poverty.

* Bruce Logan is a former Auckland schoolteacher now living in France.